1. Field of the Invention
The present invention relates to a method of producing underground pipes by pressing ahead pipe section into the ground, and also relates to an apparatus for carrying out such a method. The ground is loosened at the head of the pipe which is to be pressed ahead, and the removed ground material is conveyed to the back through the pipe for removal or processing. Supply lines run to the outside from the head of the pipe through the individual pipe sections. The apparatus includes at least one pressing unit for the pipe, as well as a guide way for the pipe.
2. Description of the Prior Art
During the production of pipes placed underground, trenching, and hence disruptive impacts on fixed and movable objects and persons above ground, can be dispensed with if the pipe, starting from a pit, is shoved or pressed through a hollow section which is cut or drilled into the ground. For pipe diameters of approximately 300 mm and greater, the pressing ahead of pipes into the ground is a known method. At the front end of the pipe, which comprises pipe sections which are placed together, and which is to be pressed in, a drilling or cutting unit is generally installed, with the aid of which the ground is loosened, is conveyed inwardly into the pipe which is to be placed, and is conveyed by suitable transporting means through the pipe, and via the pit, to the surface of the ground.
With this heretofore known method, it is necessary to install supply and removal lines through the pipe which is to be placed up to the removal equipment in the front region of the pipe. In particular, such lines are necessary for supplying power and water, and in certain cases compressed air, and for transmitting measuring and control data. However, every time a new pipe section is introduced and connected, these lines must be interrupted, guided through the new pipe section, and reconnected. During this reconstruction work, no advancement of the pipe can, of course, occur, and the removal operations in the front part of the pipe must be halted. When compressed air is used to brace or shore the work face, this supply of compressed air at the front end of the pipe should only be interrupted for a short period of time, so that in particular by-pass lines must make possible a short period of interruption when a new pipe section is introduced. In many cases it has been shown that considerably more time must be used for the reconstruction, during which the actual advancement operation is halted, than is required for the actual advancement of the corresponding pipe section. Thus, the reconstruction of the lines during introduction of a new pipe section is particularly disadvantageous for a speedy and efficient construction progress, and for a safe and reliable supply of the cutting or driving machine.
An object of the present invention is to provide a method and apparatus with which it is possible to achieve a quasi-continuous or continuous pressing advancement of a pipe into the ground without having long interruptions for the reconstruction of supply lines.